1. Field of the Invention
The present invention generally relates to a technique for displaying an image space and, more particularly, to an image space display method and apparatus for spatially displaying features of image.
2. Description of the Related Art
As for such a technique for displaying an image space, there are following techniques:
1) “A User Interface Visualizing feature Space for Content-Based Image Retrieval”, Technical Report of IEICE, IE98-204; and
2) “Visual Interaction for Exploration in Information Space of Documents”, Journal of JSSST, Vol.13.
The above-mentioned known technique 1) is a method for mapping image features on a display space of a 2-dimensional by reducing the number of dimensions of a multidimensional space according to principal component analysis. The above-mentioned known technique 2) introduces an idea of dynamic updating of visualized results in a visual classification technique where the updating is performed in response to a user operation, and the visual classification is given by arranging a large number of documents and keywords based on their mutual relationships.
However, the known technique 1) has a problem in that principal component analysis cannot be carried out when image features cannot be represented by vector data or when image similarity between images cannot be represented by a linear function. The known technique 2) has a drawback in that the number of keywords becomes large due to a large amount of computation, which makes a processing time lengthy, thereby making it unsuitable for interactive presentation.
On the other hand, when a plurality of features area extracted from an image so as to display the feature space thereof on a 3-dimensinal or 3-dimensional display space, a user can easily grasp the feature space if the features are assigned to the respective dimensional axes so as to give sense to each dimensional axis.